Spanish fashion chain Zara, now the world's largest retailer, is being accused of missing a "huge opportunity" in the Unites States by refusing to offer plus-size clothing to women.

Zara has beaten out major retailers like Forever 21 or H&M in the "fast fashion" market, which introduces a new line of fashion-forward, low cost clothing every two weeks. But one thing you won't find on their racks at the chain's stores across America is larger sizes. According to a recent New York Times article, that is no design flaw. Larger sizes cost more to make.

Across the globe there are nearly 1,700 Zara stores, but in the U.S, there are only a few dozen, and experts say Zara isn't expanding more in the U.S. because the country has a problem with expanding waistlines. More than one-third of U.S. adults -- 35.7 percent -- are obese, according to the Centers for Disease Control and Prevention. France, by comparison has 11.3 percent obesity rate in 2004, the lowest in Europe.

Fashion bloggers Shainna Tucker and Alissa Wilson, who are both size 18 and say they can usually fit into XL or 1XL, told ABC News that though they are frustrated that large retailers continue to "ignore" their sector and said "our money is as good as anyone else's," they add that it's something the fashion brand is actually able to get away with.

"They feel like they can," Wilson said. "As if plus-sized women are like aliens, we came from Mars [or] somewhere."

On a shopping trip to Zara, both Tucker and Wilson said that they weren't able to fit into the clothing.

Although Americans are in fact more obese than the populations of most foreign countries, unlike Zara, other European and Japanese retailers have seized the American waistline by the belt, and are making millions.

"Zara is missing a huge opportunity here in the United States," Adweek's Tony Chase said. "H&M and Uniqlo have done tremendous business here. Other retailers have done it here. I don't know why it would be an issue for Zara, and they have done business here."

Chase adds that the retailer already has 45 stores in the U.S., and that other retailers that do offer plus-sizes are on target to have more stores, and expand even further.

"I don't know why in this sector, the fast fashion sector, the retailer would opt to not be aggressive," he said. "Why are you even playing if you are not going to be aggressive in a market?"

Still, there are plenty of women that are just a size 6 or a size 8, but in Zara, they are large and extra large.

"If [a size 8 is] trying on an extra large -- imagine us," Wilson said. "We are going in there with our MacGyver eye – like, 'how can we make this work.'"

Tucker and Wilson have found some innovative ways to make the clothes at Zara work for them, by turning a skirt into a tube top, and even finding ways into the smaller sizes, like buying the store's tops because they are more likely to fit than a bottom.

They say that the brands' petite-sized clothing is no match for their quest for the perfect find.

"I still love Zara as a brand," Tucker said. "To be perfectly honest, if the options they have are still trendy, it is still a place to go look. I love their handbags and shoes. I still have a place somewhere in my heart for Zara."

When contacted by ABC News, a representative for Zara said that the retailer's "expansion pace in the U.S. market remains as planned, with several new openings scheduled for next year." The representative did not comment on ABC News' queries on sizing considerations within the U.S.